Parenteral solutions of riboflavin and the like



Patented Jan. 18, 1949 PARENTERAL SOLUTIONS OF RIBOFLAVIN AND THE LIKE Tillman D. Gerlough, Highland Park, and Emil L. SmithyNew Brunswick, N. J.', assignors to E. R. Squibb & Sons, New York,N. Y., a corporation of New York i No Drawing. Application June 27, 1946,

l Serial No. 679,857

Claims. 1

This invention relates to parenteral (i. e., parenterally-administrable) solutions of 9-polyhydroxyalkyl-iso-alloxazins, especially riboflavin (6,7-dimethyl-Q-d-ribityl-iso-alloxazin) The parenteral solutions of 9-po1yhydroxyalky1- iso-alloxazins heretofore available have been unsatisfactory for various reasons, as illustrated by the case of riboflavin, for example. The solubility of riboflavin in water is about 125 micrograms per ml. supersaturated solutions containing as high as about 250 micrograms per ml. have been prepared; but the riboflavin content of such solutions is still so low as to necessitate the administration of a parenterally-undesirable volume of solution. Relatively high-concehtratioh solutions have been obtained by dissolving the riboflavin in aqueous solutions of certain substances,

interalia, urea, N-methylacetamide, acetamidine hydrochloride, liver extract, and nicotinic acid amide; but none of these riboflavin solutions have been found wholly satisfactory. Thus, some of them are unstable, particularly when sterilized by heating; some of the substances used to solubilize the riboflavin are pharmacodynamicallyobjectionable; and some of these substances must be employed in objectionably high proportion to attain the desired riboflavin solubility. [By pharmacodynamically-objectionable is meant, of course, that the substance has an objectionable action in the body when administered in the amount required to solubilize the riboflavin] It is the object of this invention to provide improved, relatively high-concentration parenteral solutions of 9-polyhydroxyalkyl-iso-alloxazins, especially riboflavin, and a method of them.

It has been found that 9-polyhydroxyalkyl-isoalloxazins can be solubilized by treating them in watergwith indoles (i. e., indole and derivatives thereof containing the indole nucleus), that the relatively high-concentration solutions thus obtainable are stable, and that-provided the indole is pharmacodynamically-unobjactionable-these solutions are suitable for parenteral administration. Riboflavin concentrations. of the order of 1.0% are readily obtainable by suchsolubilization. Thus, with a 10% aqueous solution of the sodium salt of acetyl-tryptophan (atpHG) as the solvent, a riboflavin concentration of about 12,000 microgramsper ml. may be attained, which solution does not deposit riboflavin even when chilled to 2 C.; and with intermediate-concentration aqueous solutions of the sodium salt of acetyl-tryptophan as the solvent, e. g., 2% and 5% (eac hat pHfi), solutions containing respectively about2,000 and preparing 5,000 micrograms of riboflavin per ml. may. be attained. The preferred indoles are those, such as the sodium salt of acetyl-tryptophan, which are pharmacodynamically-inactive, i. e., have no appreciable action in the body (other than. nutritional).

The improved, relatively high-concentration parenteral solutions .of 9-polyhydroxyalkyl-iso alloxazins of this invention essentially comprise a 9-polyhydroxyalkyl-iso-alloxazin (preferably riboflavin), water, and a pharmacodyna'micallyunobjectionable indole (preferably thesodium salt of acetyl-tryptophan), the 9-polyhydroxyalkyl-iso-alloxazin being in a concentration higher than that obtainable in the absence of the indole. The method of this invention comprises heating the 9-polyhydroxyalkyl-iso-alloxazin and the pharmacodynamically-unobjectionable indole in water to such temperature and/or for such tim as required to effect solubilization.

The compositions of this invention may (an preferably do) contain one or more additional therapeutic-especially vitaminiccomponents, inter alia, thiamine hydrochloride, niacinarnide, andliver extract. Some of these additional components are solubilizing agents for 9-polyhydroxyalkyl-iso-alloxazins, and may act as such in the compositions of this invention; but inasmuch as the concentration of 9-polyhydroxyalkyl iso-alloxazin specified for the compositions of this invention is higher than that obtainableain the absence of the indole, the solubilizing action of the indole is utilized regardless of the inclusion of these additional solubilizing agents. p

The indoles preferred for the purposes of this invention'are the pharmacodynamically-unobjectionable compounds of the general formula where R. is a member of the group consisting of H and aliphatic radicals, inter alia l-tryptophan dl-tryptophan Acetyl-tryptophan N-methyl-tryptophan dl-indole lactate Indoleacetic acid fi-Indolepyruvic acid, fi-lndolyl propionie acid fi-Indolylbutyrlc acid p-Indoleacrylic acid invention The acidic indoles listed hereinabove, partially or Wholly neutralized with alkali The pharmacodynamically-unobjectionable alkali salts (i. e., alkali-metal, alkaline-earth-metal, and ammonium salts) 01? the acids as the general formula nutritionally adequate; and essential ior "the growth'of mammals). I

It is believed that the solubilizing action of the in'd'ol'es on the!) polyhydroxyalkyl iso alloxaz'ins 'is due t'o'the formation of'a loose compound or complex, which compound or complex'in-the body is capable of "yielding, onha's the effect of {the the indoles hasthesame molar solubilizing efiec't;

e. g,an aqueous solution of one mo-1of"part-rally-- neutralized aeetyl tryptophan will dissolve the safr'ie amount'of riboflavin as an aqueoussolution of enamel-pf indoleacetio acid (at thesameipri) moreover, unlike the solubilityor ritbfiav'in in water aldn'e. the "solubilitybfiiboflavinin an 'a'qneous seiutienor aninnme-is as gieat-at 2 '0. as at 87 Ct'r greater (which, *shre'sthat riboflavin solutions or =th'is' invention will not erystamze out "at w tem erature).

dentall as- However, it is not attendee thfat thi s' invention henna-en by any tneoretien eaner-rattan.

emao1es-are; in general; soluble in hot water eencenn-ation solutioh's or '9'-' pairequation.

I I Tfie'solubility "6f 'acet i tryptopnan '(anniienc'e the coneentration of 9=polyhydroxyalliyliso- 'allotia't'in emanate) varies with the pH. 'An acid pH (especially beldw' about "515) isprerei-reu where the 'solutionis to contain thi'afninehydrochloride.

The invention is applicable generally to "solutions ei 9:pelyhyarexyalkyl isbaiiexanns, ant-e1- alia, 6,7-dimethyl-9-l-arabityl-iso-alloxazin and 6,7 dimethyl 9 d"- ribityl-iso-alloxazin (riboflavin).

The following examples are illustrative of the w re 1 100 g. acetyl-tryptophan and 5 g. chlorobutanol are added to suflicient water to make one-liter of solution, and the pH is adjusted to'fi'il'by means of sodium hydroxide. Then 1 2 riboflavin is added, and the mixture is'heate'dtoiili' "Cqand held at that temperature for a sh'ort-timefiintil rendered sterile (e. g., by heating); an-were iii) tions, and the filled and sterilized ampules, are preferably protected from light, as riboflavin is decomposed thereby.

The resulting composition is a stable solution, suitable for parenteral administration in the treatment of conditions involving a severe deficiency of riboflavin. The chlorobutanol used is not an essential component of the solution, being'included as a preservative when the solution is tobe packaged in multiple-dose ampules.

Example 2 ''A stable solution containing per ml.:

mg. 1:, Riboflavin l0 1 Thiamine hydrochloride "Ni'aoinamide 100 Acetyl-tryptophan 100 is obtained as follows; the acetyl-tryptophan is added to the waterrthe pH is adjusted to 5.0 by means of sodium hydroxide; the riboflavin and niacinainide are added; the mixture is heated (to about -85? C.) to erfect solution; the solution is cooled to room temperature; and the thiamine hydrochloride is added. The solution is'then sterile-filtered, and packaged in'ampules. The thus-obtained solution is suitable for parenteral administration in the treatment of conditions involving a severe: deficiency of ribofia'v in j as 7 well as of thiamine hydrochloride and hia'ihaini'de.

Example 3 35 A stable solution containing per ml:

4 a l v mg. Riboflavin 9 Thiamine hydrochloride {9 Niacinamide {15 4O Acetyl-tryptophan l is prepared "in the same manner 'as'tnat in Exam ne 2. This solution isa more balanced vita'minie "preparation than that described I in Example zysupplying per ml; three times the daily minimum re uirement of each of the three vitamins.

Example 4 A stable solution containing per ml;

i Mg. Riboflavin a; 10 Thiamine hydrochloride"; -10 Niacinamide 1 Acetyl-tryptophan l 80 Liver extract (solids) 300 is prepared in the same manner as that in Ex- "ample z, using an aqueous extract of mammalian liver (containing the vitamin-.B-complex and antiahe'mia fractions of the liver) in place of the waterin the procedure described in Example '2 The invention has been illustrated in theforegoing examples "only in iconne'ction with the pre- 'solubilization with the sodium salt of tryp'tophan but inasmuch as the prob n oiaddit'ionalexamples requires merely replacing the acetyl-tryptophan by equimolecular amounts of other pharmacodynamically-unobjectiona'ble indoles at thesame H, inter alia, indoleacetic 'a'cidand tryptophan, no further exempliiica ion'appears to 'be required. The invention ma be variously otherwise em bo ed 'wlthinthe scope of the appended'claims.

aim:

1. hparentera'i seiuuon essennany'comprisin water, a pharmacodynamically unobjectionable indole, and a 9-polyhydroxyalkyl-iso-alloxazln in a concentration higher than that obtainable in the absence of the lndole.

2. A parenteral solution essentially comprising water, a pharmacodynamically unobjectionable indole, and riboflavin in a concentration higher than that obtainable in the absence of the indole.

3. A parenteral solution essentially comprising water, a pharmacodynamically unobjectionable alkali salt of an acid of the general formula H-Rl-O O OH riboflavin in a concentration higher than that obtainable in the absence of said salt.

4. A parenteral solution essentially comprising water, the sodium salt of acetyl-tryptophan, and riboflavin in a concentration higher than that obtainable in the absence of said salt.

6 a 5. A parenteral solution essentially comprising water, a pharmacodynamically unobjectionable indole, and riboflavin in a concentration higher than that obtainable in the absence of the indole, the concentration being of the order of 1.0%.

TILLMAN D. GERLOUGH. EMIL L. SMITH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,256,604 Auhagen Sept. 23, 1941 2,349,986 Preiswerk May 30, 1944 2,388,261 Frost Nov. 6, 1945 OTHER REFERENCES New Modern Drugs, Jan. 1943, 9th supplement, pages 20, 22. 

